An optical-chemical sensor using pyrene-sulfonic acid for unsteady surface pressure measurements

The commonly-held assumption that the aerodynamics of rectangular prisms with sharp edges are insensitive to Reynolds number is shown to have limitations. Flow reattachment on the top and/or bottom of the prisms can be related to Reynolds number, Re. Steady and unsteady surface pressure measurements were carried out on nine different rectangular prisms for Re from 0.3×106 to 2.5×106 at several angles of attack, in smooth and turbulent flow. It was observed that the reattachment was dependent on parameters such as fineness ratio, edge treatment, angle of attack, turbulence of the oncoming flow and Reynolds number. Permanent reattachment occurred for prisms with fineness ratio of 4 and fluctuating reattachment took place for rectangular prisms with fineness ratio as low as 2.

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An investigation of the mechanisms causing large-amplitude wind-induced vibrations in stay cables using unsteady surface pressure measurements

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/j.jweia.2018.10.004 ◽

2018 ◽

Vol 183 ◽

pp. 19-34 ◽

Cited By ~ 5

Author(s):

Sean McTavish ◽

Arash Raeesi ◽

Annick D'Auteuil ◽

Kunihiro Yamauchi ◽

Hiroshi Sato

Keyword(s):

Surface Pressure ◽

Large Amplitude ◽

Pressure Measurements ◽

Stay Cables ◽

Unsteady Surface Pressure

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Identification of boundary layer structures by unsteady surface pressure measurements

10.2514/6.2022-1649 ◽

2022 ◽

Author(s):

Laura Botero ◽

Eki Liptiay ◽

Cornelis H. Venner ◽

Leandro D. de Santana

Keyword(s):

Boundary Layer ◽

Surface Pressure ◽

Pressure Measurements ◽

Layer Structures ◽

Unsteady Surface Pressure

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Influence of Clocking and Vane/Blade Spacing on the Unsteady Surface Pressure Loading for a Modern Stage and One-Half Transonic Turbine

Volume 6: Turbo Expo 2003, Parts A and B ◽

10.1115/gt2003-38724 ◽

2003 ◽

Cited By ~ 3

Author(s):

C. W. Haldeman ◽

M. L. Krumanaker ◽

M. G. Dunn

Keyword(s):

Fundamental Frequency ◽

Surface Pressure ◽

Pressure Measurements ◽

Pressure Loading ◽

Unsteady Pressure ◽

Spacing Effects ◽

Unsteady Surface Pressure ◽

Transonic Turbine ◽

Vane Clocking ◽

Experimental Effort

This paper describes pressure measurements obtained for a modern one and one-half stage turbine. As part of the experimental effort, the position of the HPT vane was clocked relative to the downstream LPT vane to determine the influence of vane clocking on both the steady and unsteady pressure loadings on the LPT vane and the HPT blade. In addition, the axial location of the HPT vane relative to the HPT blade was changed to investigate the combined influence of vane/blade spacing and clocking on the unsteady pressure loading. Time-averaged and time-accurate surface-pressure results are presented for several spanwise locations on the vanes and blade. Results were obtained at four different HPT vane-clocking positions and at two different vane/blade axial spacings for three (of the four) clocking positions. For time-averaged results, the effect of clocking is small on the HPT blade and vane. The influence of clocking on the transition ducts and the LPT vane is slightly greater (on the order of ±1%). Reduced HPT vane/blade spacing has a larger effect than clocking on the HPT vanes and blades (±3%) depending upon the particular surface. Examining the data at blade passing and the first fundamental frequency, the effect of spacing does not produce a dramatic influence on the relative changes that occur between clocking positions. The results demonstrate that clocking and spacing effects on the surface pressure loading are very complex and may introduce problems if the results of measurements or analysis made at one span or location in the machine are extrapolated to other sections.

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